diff --git a/.github/workflows/playwright.yaml b/.github/workflows/playwright.yaml
index 57fd8e3f..e6f17d85 100644
--- a/.github/workflows/playwright.yaml
+++ b/.github/workflows/playwright.yaml
@@ -9,7 +9,7 @@ on:
 jobs:
     playwright:
         name: "Playwright Tests"
-        runs-on: ubuntu-latest
+        runs-on: ubuntu-22.04
         steps:
             - name: "Checkout repository"
               uses: "actions/checkout@v4"
diff --git a/piccolo_admin/endpoints.py b/piccolo_admin/endpoints.py
index f1872385..6405a070 100644
--- a/piccolo_admin/endpoints.py
+++ b/piccolo_admin/endpoints.py
@@ -100,13 +100,13 @@ class GroupItem(BaseModel):
 
 
 class GroupedTableNamesResponseModel(BaseModel):
-    grouped: t.Dict[str, t.List[str]] = Field(default_factory=list)
+    grouped: t.Dict[str, t.List[str]] = Field(default_factory=dict)
     ungrouped: t.List[str] = Field(default_factory=list)
 
 
 class GroupedFormsResponseModel(BaseModel):
     grouped: t.Dict[str, t.List[FormConfigResponseModel]] = Field(
-        default_factory=list
+        default_factory=dict
     )
     ungrouped: t.List[FormConfigResponseModel] = Field(default_factory=list)
 
@@ -680,7 +680,7 @@ def __init__(
 
         private_app.add_route(
             path="/change-password/",
-            route=change_password(
+            route=change_password(  # type: ignore
                 login_url="./../../public/login/",
                 session_table=session_table,
                 read_only=read_only,
@@ -786,7 +786,7 @@ def __init__(
 
         public_app.add_route(
             path="/logout/",
-            route=session_logout(session_table=session_table),
+            route=session_logout(session_table=session_table),  # type: ignore
             methods=["POST"],
         )
 
diff --git a/requirements/test-requirements.txt b/requirements/test-requirements.txt
index 3ce95ac8..d63cc378 100644
--- a/requirements/test-requirements.txt
+++ b/requirements/test-requirements.txt
@@ -4,9 +4,5 @@ flake8==7.0.0
 piccolo[postgres,sqlite]>=1.16.0
 playwright==1.41.2
 pytest-playwright==0.4.4
-httpx>=0.20.0
-# This is needed because newer versions of FastAPI use a Starlette version with
-# a `TestClient` which breaks rate limiting.
-# The changes to `TestClient` will likely be reverted in a future release, in
-# which case we can remove this version pin.
-fastapi==0.106.0
+httpx==0.28.1
+fastapi==0.115.6